The philosophy/religion of Thelema (Greek, Qelema,
"Will") is founded upon Liber AL vel Legis: The Book of the Law.
Dictated to the prophet Aleister Crowley on April 8, 9, and 10 in 1904,
this 220 verse Holy Book proclaims the Equinox of the Gods, when Horus
took the throne of Ra in place of his father, Osiris. This having
taken place, the magickal formulae governing the universe have also changed.

This process of the Equinox of the Gods results
in a procession of the Aeons, with the present Aeon being that of Horus,
the Crowned and Conquering Child. These Aeons last approximately
2000 years, and essentially "govern" the destinies of the planet.
The gods upon the throne can be understood as the aggregate of human experience,
or the collective psyche of the human race. In the history of the
human race, there have been three of these Aeons.

The first Aeon is that of Isis, the mother, when
the Universe was conceived as simple nourishment drawn directly from her;
this period is marked by matriarchal government. Next, beginning
approximately 500 BCE, Osiris, the father.